Comparative assessment of skeletal muscle mass using computerized tomography and bioelectrical impedance analysis in critically ill patients

Advancing body composition assessment in patients with cancer: First comparisons of traditional versus multicompartment models

BACKGROUND AND AIMS

Measurement of body composition using computed tomography (CT) scans may be a viable clinical tool for low muscle mass assessment in oncology. However, longitudinal assessments are often infeasible with CT. Clinically accessible body composition technologies can be used to track changes in fat-free mass (FFM) or muscle, though their accuracy may be impacted by cancer-related physiological changes. The purpose of this study was to examine the agreement among accessible body composition method with criterion methods for measures of whole-body FFM measurements and, when possible, muscle mass for the classification of low muscle in patients with cancer.

METHODS

Patients with colorectal cancer were recruited to complete measures of whole-body DXA, air displacement plethysmography (ADP), and bioelectrical impedance analysis (BIA). These measures were used alone, or in combination to construct the criterion multicompartment (4C) mode for estimating FFM. Patients also underwent abdominal CT scans as part of routine clinical assessment. Agreement of each method with 4C model was analyzed using mean constant error (CE = criterion - alternative), linear regression including root mean square error (RMSE), Bland-Altman limits of agreement (LoA) and mean percentage difference (MPD). Additionally, appendicular lean soft tissue index (ALSTI) measured by DXA and predicted by CT were compared for the absolute agreement, while the ALSTI values and skeletal muscle index by CT were assessed for agreement on the classification of low muscle mass.

RESULTS

Forty-five patients received all measures for the 4C model and 25 had measures within proximity of clinical CT measures. Compared to 4C, DXA outperformed ADP and BIA by showing the strongest overall agreement (CE = 1.96 kg, RMSE = 2.45 kg, MPD = 98.15 ± 2.38%), supporting its use for body composition assessment in patients with cancer. However, CT cutoffs for skeletal muscle index or CT-estimated ALSTI were lower than DXA ALSTI (average 1.0 ± 1.2 kg/m2) with 24.0% to 32.0% of patients having a different low muscle classification by CT when compared to DXA.

CONCLUSIONS

Despite discrepancies between clinical body composition assessment and the criterion multicompartment model, DXA demonstrates the strongest agreement with 4C. Disagreement between DXA and CT for low muscle mass classification prompts further evaluation of the measures and cutoffs used with each technique. Multicompartment models may enhance our understanding of body composition variations at the individual patient level and improve the applicability of clinically accessible technologies for classification and monitoring change over time.

Long-Term Rehabilitation Therapy Is Effective for Physical Function in a Patient With Amyloid Light Chain Amyloidosis Complicated by Nephrotic Syndrome: A Case Report and Literature Review

We report on the rehabilitation of a patient with amyloid light chain (AL) amyloidosis complicated by nephrotic syndrome. Various symptoms produced by AL amyloidosis, including nephrotic syndrome, complicate rehabilitation therapy. In this case report, long-term physical therapy was initiated prior to autologous peripheral blood stem cell transplantation owing to the risk of further decline in physical function due to decreased mobility and physical activity. Patients were instructed on how to perform home exercise therapy. Furthermore, compliance was monitored using a checklist and regular face-to-face feedback. There was no increase in skeletal muscle mass, but improvements in grip strength, lower extremity muscle strength, and phase angle were observed after 24 weeks of physical therapy. Despite the absence of partial remission (urinary protein level of 3.5 g/gCre or higher), nephrotic syndrome demonstrated a trend toward improvement. Since the effectiveness of physical therapy in such patients has not yet been fully established, this report suggests that long-term rehabilitation therapy for physical function in patients with nephrotic syndrome complicated by persistent proteinuria may be effective.

Association of sarcopenia defined by different skeletal muscle mass measurements with prognosis and quality of life in older patients with heart failure

BACKGROUND

Diagnosing sarcopenia in heart failure (HF) patients is important, but how to assess skeletal muscle mass in HF patients with fluid retention is controversial. We aimed to examine the association between sarcopenia, defined by different skeletal muscle mass measurements, and clinical outcomes in older HF patients.

METHODS

We included 546 older HF patients (≥ 65 years) who were assessed for sarcopenia at discharge (median age 77 years, 309 males). Sarcopenia was diagnosed using grip strength, usual gait speed, and skeletal muscle mass according to international criteria. We used mid-upper arm circumference (MUAC), mid-upper arm muscle circumference (MAMC), calf circumference (CC), and skeletal muscle mass index (SMI) assessed by bioelectrical impedance analysis to assess skeletal muscle mass and defined sarcopenia in each of these measurements. Prognostic outcomes were composite events (all-cause death and HF rehospitalization) and cardiovascular disease (CVD) events (CVD death and CVD rehospitalization). Quality of life (QOL) was assessed using the 36-item Short-Form Health Survey physical functioning (SF-36PF) score.

RESULTS

The sarcopenia defined by MUAC [hazard ratio (HR): 2.50; 95 % confidence interval (95 % CI): 1.64-3.81; p < 0.001] or MAMC (HR: 1.98; 95 % CI: 1.35-2.92; p = 0.001) were associated with higher composite event rates than the non-sarcopenia. The sarcopenia defined by MUAC (HR: 1.88; 95 % CI: 1.25-2.83; p = 0.002) or MAMC (HR: 1.70; 95 % CI: 1.16-2.49; p = 0.007) were associated with higher CVD event rates than the non-sarcopenia. The sarcopenia defined by CC or SMI were not associated with prognoses. The sarcopenia defined by MUAC, MAMC, or CC were associated with low SF-36PF scores (all p < 0.05).

CONCLUSIONS

These results suggest that a diagnosis of sarcopenia based on MUAC or MAMC rather than CC or SMI reflects prognosis and QOL in older HF patients.

Opportunistic screening for long-term muscle wasting in critically ill patients: insights from an acute pancreatitis cohort

OBJECTIVES

To assess the feasibility of long-term muscle monitoring, we implemented an AI-guided segmentation approach on clinically indicated Computed Tomography (CT) examinations conducted throughout the hospitalization period of patients admitted to the intensive care unit (ICU) with acute pancreatitis (AP). In addition, we aimed to investigate the potential of muscle monitoring for early detection of patients at nutritional risk and those experiencing adverse outcomes. This cohort served as a model for potential integration into clinical practice.

MATERIALS

Retrospective cohort study including 100 patients suffering from AP that underwent a minimum of three CT scans during hospitalization, totaling 749 assessments. Sequential segmentation of psoas muscle area (PMA) was performed and was relative muscle loss per day for the entire monitoring period, as well as for the interval between each consecutive scan was calculated. Subgroup and outcome analyses were performed including ANOVA. Discriminatory power of muscle decay rates was evaluated using ROC analysis.

RESULTS

Monitoring PMA decay revealed significant long-term losses of 48.20% throughout the hospitalization period, with an average daily decline of 0.98%. Loss rates diverged significantly between survival groups, with 1.34% PMA decay per day among non-survivors vs. 0.74% in survivors. Overweight patients exhibited significantly higher total PMA losses (52.53 vs. 42.91%; p = 0.02) and average PMA loss per day (of 1.13 vs. 0.80%; p = 0.039). The first and the maximum decay rate, in average available after 6.16 and 17.03 days after ICU admission, showed convincing discriminatory power for survival in ROC analysis (AUC 0.607 and 0.718). Both thresholds for maximum loss (at 3.23% decay per day) and for the initial loss rate (at 1.98% per day) proved to be significant predictors of mortality.

CONCLUSIONS

The innovative AI-based PMA segmentation method proved robust and effortless, enabling the first comprehensive assessment of muscle wasting in a large cohort of intensive care pancreatitis patients. Findings revealed significant muscle wasting (48.20% on average), particularly notable in overweight individuals. Higher rates of initial and maximum muscle loss, detectable early, correlated strongly with survival. Integrating this tool into routine clinical practice will enable continuous muscle status tracking and early identification of those at risk for unfavorable outcomes.

Comparison of bioelectrical impedance analysis and computed tomography for the assessment of muscle mass in patients with gastric cancer

BACKGROUND

Low muscle mass was significantly correlated with poor clinical outcomes in cancer patients. This study aimed to compare the differences between bioelectrical impedance analysis (BIA) and computed tomography (CT) in measuring skeletal muscle mass and detecting low muscle mass in patients with gastric cancer (GC).

METHOD

This cross-sectional study included a total of 302 consecutive patients diagnosed with GC at our institution from October 2021 to March 2023. CT images were analyzed at the L3 level to obtain the cross-sectional area of skeletal muscle, which was subsequently used for calculating whole-body skeletal muscle mass via the Shen equation and skeletal muscle tissue density. BIA was utilized to measure skeletal muscle mass using the manufacturer's proprietary algorithms. Skeletal muscle mass (kg) was divided by height squared (m2) to obtain skeletal muscle index (SMI, kg/m2). Pearson's correlation coefficient was performed to assess the correlation between SMI measured by BIA and CT. The agreement between the two methods was assessed using Bland-Altman analyses. The clinically acceptable agreement was defined as the 95% limits of agreement (LOA) for the percentage bias falling within ± 10%. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of BIA in identifying low muscle mass.

RESULTS

A total of 59 patients (19.5%) were identified as having low muscle mass based on CT analysis, whereas only 19 patients (6.3%) met the criteria for low muscle mass according to BIA analysis. BIA-measured SMI showed a strong positive correlation with CT-measured SMI in all patients (r = 0.715, P < 0.001). With Bland-Altman analysis, there was a significant mean bias of 1.18 ± 0.96 kg/m2 (95% CI 1.07-1.29, P < 0.001) between SMI measured by BIA and CT. The 95% LOA for the percentage bias ranged from -7.98 to 33.92%, which exceeded the clinically acceptable range of ± 10%. A significant difference was observed in the mean bias of SMI measured by BIA and CT between patients with and without GLIM malnutrition (1.42 ± 0.91 kg/m2 versus 0.98 ± 0.96 kg/m2, P < 0.001). The cut-off values for BIA-measured SMI in identifying low muscle mass using CT as the reference were 10.11 kg/m2 for males and 8.71 kg/m2 for females (male: AUC = 0.840, 95% CI: 0.772-0.908; female: AUC = 0.721, 95% CI: 0.598-0.843).

CONCLUSIONS

Despite a significant correlation, the values of skeletal muscle mass obtained BIA and CT cannot be used interchangeably. The BIA method may overestimate skeletal muscle mass in GC patients compared to CT, especially among those with GLIM malnutrition, leading to an underestimation of low muscle mass prevalence.

Clinical practice guidelines for nutritional assessment and monitoring of adult ICU patients in China

The Chinese Society of Critical Care Medicine (CSCCM) has developed clinical practice guidelines for nutrition assessment and monitoring for patients in adult intensive care units (ICUs) in China. This guideline focuses on nutrition evaluation and metabolic monitoring to achieve optimal and personalized nutrition therapy for critically ill patients. This guideline was developed by experts in critical care medicine and evidence-based medicine methodology and was developed after a thorough review of the system and a summary of relevant trials or studies published from 2000 to July 2023. A total of 18 recommendations were formed and consensus was reached through discussions and reviews by expert groups in critical care medicine, parenteral and enteral nutrition, and surgery. The recommendations are based on currently available evidence and cover several key fields, including screening and assessment, evaluation and assessment of enteral feeding intolerance, metabolic and nutritional measurement and monitoring during nutrition therapy, and organ function evaluation related to nutrition supply. Each question was analyzed according to the Population, Intervention, Comparison, and Outcome (PICO) principle. In addition, interpretations were provided for four questions that did not reach a consensus but may have potential clinical and research value. The plan is to update this nutrition assessment and monitoring guideline using the international guideline update method within 3-5 years.

Evaluation of the cachexia index using a bioelectrical impedance analysis in elderly patients with non-Hodgkin's lymphoma: A single-center prospective study

Cancer cachexia is a disorder that affects patient outcomes. The present study prospectively evaluated the prognostic value of the cachexia index (CXI) in elderly patients with non-Hodgkin's lymphoma (NHL). We prospectively analyzed 51 elderly patients who were diagnosed with NHL at our institution. CXI was calculated as follows: CXI = SMI × Alb/NLR (SMI: skeletal muscle index, Alb: serum albumin, NLR: neutrophil-to-lymphocyte ratio). SMI was measured by a bioelectrical impedance analysis (BIA) using the InBody 720. We determined the sex-specific cutoff values of the CXI by a receiver operating characteristic curve analysis and divided all patients into low- and high-CXI groups. The median age at the diagnosis was 78 years (60-93 years), and 28 (55%) were male. The histologic subtypes were B-cell lymphoma in 49 patients and T-cell lymphoma in 2. Twenty-eight (55%) patients were categorized into the high-CXI group, and 23 (45%) were categorized into the low-CXI group. The overall survival (OS) in the low-CXI group was significantly shorter than that in the high-CXI group (3-year OS, 70.4% vs. 95.7%, p = 0.007). Among 23 patients with DLBCL, patients with low-CXI had shorter OS than those with high-CXI (3-year OS, 55.6% vs. 92.9%, p = 0.008). On the other hand, sarcopenia had less impact on the clinical outcome of DLBCL patients. Low-CXI was associated with poor outcomes in elderly NHL and the CXI may be a clinical useful index for predicting prognosis. Further large prospective studies are needed to verify this conclusion.

Prognostic value of overhydration and bioelectrical impedance vector on short- and long-term outcomes in hospitalized patients with cancer

BACKGROUND & AIMS

Water, an essential component of body composition, appears to be a significant predictor of adverse outcomes in clinical populations, despite being frequently underexplored. Bioelectrical impedance analysis (BIA) and vector analysis (BIVA) are easy and cost-effective bedside tools for estimating body composition, particularly water content. Therefore, our study aimed to assess the impact of hydration and fluid status using both BIA and BIVA on outcomes in hospitalized patients with cancer.

METHODS

A prospective cohort study involving hospitalized individuals with cancer was conducted. Total body water (TBW) was estimated using BIA. Extracellular-water/TBW (ECW/TBW) and ECW/intracellular-water (ECW/ICW) ratios were calculated. BIVA ellipses vectors were constructed to enhance our analysis of hydration status. Participants were followed during their hospital stay and up to six months after discharge to assess outcomes, including in-hospital mortality, 6-month non-elective rehospitalization, and 6-month mortality.

RESULTS

TBW, ECW/TBW, ECW/ICW ratios, and BIVA plots were not associated with non-elective rehospitalization during the follow-up period. However, TBW and an elevated ECW/ICW ratio were independent predictors of in-hospital mortality [hazard ratio (HR): 1.07 (1.01; 1.13) p = 0.020; HR: 4.23 (1.69; 10.58) p = 0.002]. Elevated ratios ECW/TBW and ECW/ICW were independent predictors of 6-month mortality [HR: 1.87 (1.10; 3.21) p = 0.022; HR: 2.49 (1.37; 4.51) p = 0.003]. BIVA vectors for in-hospital and 6-month mortality shifted significantly to the right, leading to cachexia and overhydration quadrants (p < 0.05).

CONCLUSION

Abnormalities related to overhydration were important predictors of short- and long-term mortality in hospitalized patients with cancer.

Bioimpedance-assessed muscle wasting and its relation to nutritional intake during the first week of ICU: a pre-planned secondary analysis of Nutriti Study

BACKGROUND

Muscle mass evaluation in ICU is crucial since its loss is related with long term complications, including physical impairment. However, quantifying muscle wasting with available bedside tools (ultrasound and bioimpedance analysis) must be more primarily understood. Bioimpedance analysis (BIA) provides estimates of muscle mass and phase angle (PA). The primary aim of this study was to evaluate muscle mass changes with bioimpedance analysis during the first 7 days after ICU admission. Secondary aims searched for correlations between muscular loss and caloric and protein debt.

METHODS

Patients with an expected ICU-stay ≥ 72 h and the need for artificial nutritional support were evaluated for study inclusion. BIA evaluation of muscle mass and phase angle were performed at ICU admission and after 7 days. Considering the difference between ideal caloric and protein targets, with adequate nutritional macronutrients delivered, we calculated the caloric and protein debt. We analyzed the potential correlation between caloric and protein debt and changes in muscle mass and phase angle.

RESULTS

72 patients from September 1st to October 30th, 2019 and from August 1st to October 30th, 2021 were included in the final statistical analysis. Median age was 68 [59-77] years, mainly men (72%) admitted due to respiratory failure (25%), and requiring invasive mechanical ventilation for 7 [4-10] days. Median ICU stay was 8 [6-12] days. Bioimpedance data at ICU admission and after 7 days showed that MM and PA resulted significantly reduced after 7 days of critically illness, 34.3 kg vs 30.6 kg (p < 0.0001) and 4.90° vs 4.35° (p = 0.0004) respectively. Mean muscle loss was 3.84 ± 6.7 kg, accounting for 8.4% [1-14] MM reduction. Correlation between caloric debt (r = 0.14, p = 0.13) and protein debt (r = 0.18, p = 0.13) with change in MM was absent. Similarly, no correlation was found between caloric debt (r = -0.057, p = 0.631) and protein debt (r = -0.095, p = 0.424) with changes in PA.

CONCLUSIONS

bioimpedance analysis demonstrated that muscle mass and phase angle were significantly lower after 7 days in ICU. The total amount of calories and proteins does not correlate with changes in muscle mass and phase angle.

Computed tomography-based abdominal sarcopenic indices and bio-impedance analysis-based skeletal muscle mass index in hemodialyzed patients

BACKGROUND AND AIMS

Information about muscle wasting in hemodialyzed patients evaluated using computed tomography (CT) is limited. The present study aimed to examine the relationships between CT-based abdominal sarcopenic indices and bio-impedance analysis (BIA)-based skeletal muscle mass index (SMMI) in these patients.

METHODS

A total of 100 consecutive maintenance hemodialyzed patients who underwent CT and BIA were included. The psoas muscle index (PMI), paraspinous muscle index (PSMI), and abdominal skeletal muscle index (ASMI) were calculated by adjusting each muscle area to the height square. The psoas muscle thickness per height (PMTH) was measured using a single cross-sectional CT image obtained at the level of the third lumbar vertebra. The relationships between these CT-based sarcopenic indices and the BIA-based SMMI were examined. Moreover, the diagnostic values of these CT-based indices for BIA-defined muscle wasting (defined by the sex-specific SMMI: males, <7.0 kg/m2; females, <5.7 kg/m2) were investigated.

RESULTS

The PMI, PMTH, PSMI, and ASMI were significantly correlated with the SMMI (r = 0.678, 0.760, 0.708, and 0.785, respectively; p < 0.0001 for all). Twenty-eight patients with reduced muscle mass determined by BIA were identified. After age-sex adjustment, a multivariate logistic regression analysis revealed that the C-statistics of the PMI, PMTH, PSMI, and ASMI for the diagnosis of low muscle mass were 0.863 (p = 0.0099), 0.870 (p = 0.013), 0.891 (p = 0.040), and 0.950 (reference), respectively.

CONCLUSIONS

CT-based abdominal sarcopenic indices presented here may be useful for evaluating muscle wasting in hemodialyzed patients; the ASMI may be the most recommended sarcopenic index for such evaluations.

Prognostic Utility of Skeletal Muscle Mass Metrics in Patients With Heart Failure

BACKGROUND

Sarcopenia is associated with risks of various adverse outcomes, and the assessment of skeletal muscle mass is necessary for its diagnosis. However, heart failure (HF) is a syndrome characterised by fluid retention, which affects muscle mass measurements. Different measurement methods have been reported to have different prognostic implications. We investigated the association between skeletal muscle mass metrics measured with the use of bioelectrical impedance analysis (BIA) and anthropometric measures and prognosis in patients with HF.

METHODS

The findings of 869 consecutive patients with HF were reviewed. We investigated the skeletal muscle mass index (SMI) measured with the use of BIA, the mid-upper arm circumference (MUAC), the arm muscle circumference (AMC), and the calf circumference (CC), and the patients were divided into 3 groups according to the sex-specific tertiles of the skeletal muscle mass metrics. The end points were all-cause death and readmission due to HF.

RESULTS

The high MUAC and AMC groups showed significantly better prognoses than their respective low groups (combined events: high MUAC group hazard ratio [HR] 0.559, 95% confidence interval [CI] 0.395-0.789 [P < 0.01]; high AMC group HR 0.505, 95% CI 0.359-0.710 [P < 0.01]), although high SMI and high CC were not associated with better prognoses.

CONCLUSIONS

Among patients with HF, MUAC and AMC are more associated with prognosis than SMI and CC, which are recommended in preexisting sarcopenia guidelines. MUAC and AMC may also be useful measures in sarcopenia assessments.

Ultrasound-based upper limb muscle thickness is useful for screening low muscularity during intensive care unit admission: A retrospective study

BACKGROUND & AIMS

Malnutrition is associated with poor outcomes. Muscle mass is an important malnutrition indicator included in Global Leadership Initiative on Malnutrition (GLIM) criteria. Although bioelectrical impedance analysis and dual-energy X-ray absorptiometry are common muscle mass assessment methods, they are unreliable during intensive care unit (ICU) admission due to the influence of dynamic fluid changes. We hypothesized that ultrasound-based upper limb muscle assessment would be useful for assessing muscularity at ICU admission.

METHODS

We retrospectively analyzed prospectively obtained ultrasound data from patients admitted to an ICU. We excluded patients without computed tomography (CT) imaging of the third lumbar vertebra within 2 days of ICU admission. Primary outcomes were the diagnostic utility of ultrasound-based upper limb muscle thickness for assessing low muscularity by CT. Low muscularity was defined as a skeletal muscle index of 36.0 cm2/m2 for males and 29.0 cm2/m2 for females at the cross-sectional area of the third lumbar vertebrae. Secondary outcomes of this study included the relationships between upper limb muscle thickness and biceps brachii muscle cross-sectional area, quadriceps femoris thickness, rectus femoris cross-sectional area.

RESULTS

Among 64 patients assessed by ultrasound, 52 had CT examination records and were included in the analysis. The mean age was 70 ± 13 years, and the mean body mass index was 23.3 ± 4.2 kg/m2. Upper limb muscle thickness had the discriminative power to assess low muscularity at an area under the curve of 0.77 (95% CI [confidence interval], 0.63-0.91); the cutoff value (26.8 cm) had 84.6% sensitivity and 66.7% specificity. The upper limb muscle index had the discriminative power to assess low muscularity at an area under the curve of 0.80 (95% CI, 0.68-0.93); the cutoff value (9.9 mm/m2) had 76.9% sensitivity and 71.8% specificity. Upper limb muscle thickness was correlated with upper limb muscle cross-sectional area, quadriceps femoris muscle thickness, rectus femoris muscle cross-sectional area (r = 0.39-0.76, p < 0.01, n = 52).

CONCLUSIONS

Ultrasound-based upper limb muscle thickness assessments can screen for low muscularity upon ICU admission.

Phase Angle, Inflammation, and Sarcopenia in Late Postoperative Roux-En-Y Gastric Bypass

Sarcopenic obesity is characterized by a disproportion between the amount of muscle to fat. Contrary to most studies evaluating parameters related to sarcopenic obesity in the elderly, this study aims to evaluate the phase angle (PhA) and sarcopenia in young individuals pre- and post-Roux-en-Y gastric bypass. A total of 69 volunteers (46 women and 23 men; 38.5 ± 8.1 years) participated in this study. Body composition and PhA were assessed using BIA. Sarcopenia was assessed using a handgrip strength test (HGS) and gait speed (GS), and appendicular lean mass (ALM) was assessed using Dual Energy X-ray Absorptiometry (DXA). The PhA was significantly lower (p < 0.0007) and the resistance (R) significantly higher (p = 0.0026) in the postoperative group. HGS was negatively correlated with R (r = -0.63669; p < 0.0001), hs-CRP (r = -0.45436; p = 0.0197), and leptin (r = -0.46505; p = 0.0043). GS was negatively correlated with R (r = -0.36220; p = 0.0254), and ALM was negatively correlated with reactance (r = -0.49485; p = 0.0034) and R (r = -0.65797; p ≤ 0.0001). PhA and other components of BIA provide a good correlation with sarcopenia, especially regarding the reduction in muscle function, in an early form, in individuals in the pre- and postoperative period of gastric bypass.

The Association between the L3 Skeletal Muscle Index Derived from Computed Tomography and Clinical Outcomes in Patients with Urinary Tract Infection in the Emergency Department

The occurrence of a critical event during a urinary tract infection (UTI) can have a significant impact on mortality. This study aimed to investigate the association between the skeletal muscle index (SMI) and critical events in patients with a UTI. From April 2019 to March 2022, a total of 478 patients who met the diagnostic criteria of a UTI and underwent an abdominal CT were included in this study. Multivariate binary logistic regression analysis was used to assess independent predictors of critical events. The primary outcome was any critical event, defined as the initiation of dialysis, invasive ventilation, initiation of vasoactive medications, cardiac arrest, or death. The UTI patients were divided into two groups: those with a low SMI (n = 93) and those with a high SMI (n = 385). In multivariate analysis, a low SMI, diabetes mellitus, altered mentality, lactate levels, and creatinine levels were identified as significant predictors of critical events. A low SMI is an independent factor associated with the occurrence of critical events in UTI patients during hospitalization. Patients with a low SMI, indicating muscle wasting, may have less resilience to infections and a higher risk of experiencing severe complications. Considering the SMI along with other clinical factors can help health care providers assess and manage UTI patients.

Detection of Sarcopenia in Patients with Liver Cirrhosis Using the Bioelectrical Impedance Analysis

Bioelectrical impedance analysis (BIA) is a body composition assessment method. We aimed to determine its accuracy in the detection of sarcopenia in patients with liver cirrhosis (LC), using skeletal muscle index (SMI) at the level of third lumbar vertebra (L3-SMI) obtained using multislice computed tomography as the reference method. Patients with LC were enrolled in the period October 2019-March 2022 and follow-ups were conducted until January 2023. Their BIA parameters were compared against L3-SMI, and BIA cut-off values were proposed using AUROC analysis. Patients underwent outcome analysis based on obtained clinical characteristics. A total of 106 patients were included. We found a fair correlation between BIA parameters with the L3-SMI. We determined cut-off values of ≤11.1 kg/m2 for BIA-SMI (Se 73%, Sp 66%, AUROC 0.737, p < 0.001) and ≤5.05° for phase angle (PA) (Se 79%, Sp 60%, AUROC 0.762, p < 0.001) in the detection of sarcopenia. The relative risk of death was 2.2 times higher in patients with skeletal muscle mass (SMM) ≤ 36.5 kg. SMM was significantly associated with outcome in Kaplan-Meier analysis. This non-invasive and simple method that showed fair performances and a very good outcome prediction could provide for the unmet need for fast and affordable detection of sarcopenia in patients with LC and should be further evaluated.

Intermittent body composition analysis as monitoring tool for muscle wasting in critically ill COVID-19 patients

OBJECTIVES

SARS-CoV-2 virus infection can lead to acute respiratory distress syndrome (ARDS), which can be complicated by severe muscle wasting. Until now, data on muscle loss of critically ill COVID-19 patients are limited, while computed tomography (CT) scans for clinical follow-up are available. We sought to investigate the parameters of muscle wasting in these patients by being the first to test the clinical application of body composition analysis (BCA) as an intermittent monitoring tool.

MATERIALS

BCA was conducted on 54 patients, with a minimum of three measurements taken during hospitalization, totaling 239 assessments. Changes in psoas- (PMA) and total abdominal muscle area (TAMA) were assessed by linear mixed model analysis. PMA was calculated as relative muscle loss per day for the entire monitoring period, as well as for the interval between each consecutive scan. Cox regression was applied to analyze associations with survival. Receiver operating characteristic (ROC) analysis and Youden index were used to define a decay cut-off.

RESULTS

Intermittent BCA revealed significantly higher long-term PMA loss rates of 2.62% (vs. 1.16%, p < 0.001) and maximum muscle decay of 5.48% (vs. 3.66%, p = 0.039) per day in non-survivors. The first available decay rate did not significantly differ between survival groups but showed significant associations with survival in Cox regression (p = 0.011). In ROC analysis, PMA loss averaged over the stay had the greatest discriminatory power (AUC = 0.777) for survival. A long-term PMA decline per day of 1.84% was defined as a threshold; muscle loss beyond this cut-off proved to be a significant BCA-derived predictor of mortality.

CONCLUSION

Muscle wasting in critically ill COVID-19 patients is severe and correlates with survival. Intermittent BCA derived from clinically indicated CT scans proved to be a valuable monitoring tool, which allows identification of individuals at risk for adverse outcomes and has great potential to support critical care decision-making.

Novel Tools to Assess Muscle Sarcopenic Process in ICU Patients: Are They Worthwhile?

Critical illness induces hypercatabolic response with severe loss of lean body mass, this being a key symptom in patients with prolonged ICU stay and is associated with acquired muscle weakness, long-term mechanical ventilation, fatigue, delayed recovery, and poor quality of life after ICU stay [...].

Predicting outcomes of continuous renal replacement therapy using body composition monitoring: a deep-learning approach

Fluid balance is a critical prognostic factor for patients with severe acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT). This study evaluated whether repeated fluid balance monitoring could improve prognosis in this clinical population. This was a multicenter retrospective study that included 784 patients (mean age, 67.8 years; males, 66.4%) with severe AKI requiring CRRT during 2017-2019 who were treated in eight tertiary hospitals in Korea. Sequential changes in total body water were compared between patients who died (event group) and those who survived (control group) using mixed-effects linear regression analyses. The performance of various machine learning methods, including recurrent neural networks, was compared to that of existing prognostic clinical scores. After adjusting for confounding factors, a marginal benefit of fluid balance was identified for the control group compared to that for the event group (p = 0.074). The deep-learning model using a recurrent neural network with an autoencoder and including fluid balance monitoring provided the best differentiation between the groups (area under the curve, 0.793) compared to 0.604 and 0.606 for SOFA and APACHE II scores, respectively. Our prognostic, deep-learning model underlines the importance of fluid balance monitoring for prognosis assessment among patients receiving CRRT.

[Routine computed tomography body composition analysis-experience in intensive care patients]

The assessment of the nutritional status of patients in the intensive care unit is recommended in current guidelines and should include the assessment of muscle status. A suitable method is the analysis of routine computed tomography (CT) scans, which are frequently performed in critically ill patients. With the help of special software, individual CT slices are processed and various parameters such as muscle area, muscle density or even the percentage of adipose tissue are displayed and quantified. It has been shown that cross-sectional acquisition of skeletal muscle in the lumbar spine correlates very well with total body muscle. There are defined, albeit population-based, cut-off values that can be used to establish diagnosis of sarcopenia. Monitoring of individualized nutritional therapy can be accomplished by assessment of repetitive CT examinations. The steadily growing body of data confirms that the method can make a valuable contribution to the assessment of body composition in intensive care medicine. Most of the currently available software requires time-consuming processing of the CT. Automated programs, which are now occasionally available and eliminate the need for most manual processing, may make the method even more attractive in the future. Ultimately, the risk of intensive transport to the CT or radiation exposure may be only justified for medical indications. Nevertheless, whenever CT is available for medical reasons, it should also be exploited for composition analysis.

Sarcopenia and COVID-19 Outcomes

Coronavirus disease 2019 (COVID-19) spread rapidly and became a severe global public health threat. Older adults have a high risk of COVID-19 and its associated mortality. Sarcopenia has emerged as a predictor of poor outcomes in COVID-19 patients, including lengthy hospital stays, mortality, intensive care unit admission, need for invasive mechanical ventilation, and poor rehabilitation outcomes. Chronic inflammation, immune dysfunction, respiratory muscle dysfunction, and swallowing dysfunction may underlie the association between sarcopenia and the poor outcomes of COVID-19 patients. Interleukin 6 receptor blockers (tocilizumab or sarilumab) are recommended for treating patients with severe COVID-19, and their therapeutic effects on sarcopenia are of great interest. This review aimed to analyze the current reports on the association between sarcopenia and COVID-19 and provide an update on the contribution of sarcopenia to the severity and adverse outcomes of COVID-19 and its underlying mechanisms. We also aimed to explore the different screening tools for sarcopenia concurrent with COVID-19, and advocate for early diagnosis and treatment of sarcopenia. Given that the fight against the COVID-19 pandemic may be long-term, further research into understanding the effects of sarcopenia in patients infected with the Omicron variant is necessary.

Revised Protein Sparing Diet in Obesity and Type 2 Diabetes Mellitus

Effective nutrition therapy is a pressing issue in obesity and type 2 diabetes mellitus (T2DM) management. As such, this research aimed to determine the performance of a revised dietary strategy built on the protein-sparing diet in obesity and type 2 diabetes mellitus with regard to obtaining a rapid and stable improvement in glucometabolic control, body weight, body composition, and energy metabolism when applying the strategy in just twenty-one days. The revised protein-sparing diet differs from the traditional protein-sparing modified fast (PSMF) because it does not include foods. The daily calorie intake of this diet is exclusively derived from Isolate whey protein in addition to a formulation of Isolate whey protein enriched with essential amino acids in free form, with the addition of lipids such as extra virgin olive oil and coconut oil as a source of medium chain fatty acids, where the latter is taken for only the first four days of the diet, together with the use, for the same duration, of extended-release metformin, as the only antihyperglycemic allowed. Anthropometric measurements, bioimpedance analysis, indirect calorimetry, and blood chemistry assessments were conducted at the beginning of the study, time 0 (T0), and at the end, time 1 (T1), i.e., on the 21st day. The main outcomes of the revised protein-sparing diet after only twenty-one days were a reduction in body weight with the predominant loss of visceral atherogenic abdominal fat and, therefore, a possible contextual reduction in ectopic fat deposits together with a simultaneous reduction in insulin resistance and normalization of insulin levels, maintenance of free fat mass and basal metabolism, restoration of metabolic flexibility, and improvement of the glucometabolic and lipidic parameters. These results demonstrate the promising potential of the revised protein-sparing diet as an "etiologic tool" in the integrated nutritional treatment of metabolic diseases such as obesity and type 2 diabetes mellitus.

Nutritional state assessed by ultrasonography, but not by bioelectric impedance, predicts 28-day mortality in critically ill patients. Prospective cohort study

BACKGROUND & AIMS

Malnutrition is a disease associated with unfavorable outcomes and high prevalence among critically ill patients. The primary aim of the study was to correlate the nutritional status of patients recently admitted to the intensive care unit (ICU) with the 28-day mortality rate. The secondary aim was to establish cut-off values for the bioelectrical impedance analysis (BIA) and ultrasonography (USG) methods for the classification of the nutritional status of critically ill patients.

METHODS

Cohort-type prospective observational study design, with the inclusion of critically ill clinical-surgical patients, ≥18 years old, mechanically ventilated. Their nutritional status was assessed by phase angle and skeletal muscle mass (using BIA), and the sectional area of the rectus femoris muscle (RFM) (using USG) within the first 48 h of ICU admission.

RESULTS

Among the patients included (n = 160), the non-survivors had lower values related to the survivors for averages of the phase angle (4.4 ± 1.5° vs 4.9 ± 1.2°; p = 0.041) and sectional area of the RFM (6.1 ± 1.6 cm²/m²vs 7.4 ± 1.8 cm²/m²; p = 0.030). Cut-off values were identified using the ROC curves for phase angle (≤4.4°), skeletal muscle mass (≤19.2 kg/m²), and sectional area of the RFM (≤5.9 cm²/m²). In multivariate logistic regression analysis, the sectional area of the RFM (≤5.9 cm²/m²) was the only independent predictor of 28-day mortality (OR = 6.08; p = 0.028). In the survival analysis, greater survival at 28 days was demonstrated for patients with phase angle >4.4° (p = 0.020) and sectional area of the RFM >5.9 cm²/m² (p = 0.001). Malnourished patients had higher mortality than nourished patients according to the phase angle (31.5% vs 15.1%, respectively; p = 0.015) and the sectional area of the RFM (38.9% vs 6.3%, respectively; p = 0.001).

CONCLUSIONS

The USG of the RFM is an efficient method for both classifying the nutritional status at ICU admission and assessing the prognosis of critically ill patients.

Comparison of body water status and its distribution in patients with non-septic infection, patients with sepsis, and healthy controls

Objective

Although fluid resuscitation is the cornerstone of treatment for sepsis, the role of body water status in sepsis is poorly understood. This study aimed to understand how body water and its distribution are modified in patients with sepsis and those with non-septic infection compared to healthy individuals.

Methods

Two groups of adults presumed to have non-septic infection (n=87) and sepsis (n=54) were enrolled in this prospective study in a single emergency department, and they were compared to sex-, age-, and height-matched (1:3 ratio) healthy controls (n=11,190) from retrospective data in a health promotion center. Total body water (TBW), intracellular water (ICW), and extracellular water (ECW), determined using direct segmental multi-frequent bioelectrical impedance analysis (InBody S10) were expressed as indices for normalization by body weight (BW). The ratio of ECW to TBW (ECW/TBW) was evaluated to determine body water distribution.

Results

TBW/BW, ICW/BW, and ECW/BW were significantly higher in the non-septic infection group than in the healthy group (P<0.001), but ECW/TBW was not significantly different (P=0.690). There were no differences in TBW/BW and ICW/BW between the sepsis and healthy groups (P=0.083 and P=0.963). However, ECW/BW and ECW/TBW were significantly higher in the sepsis group than in the healthy group (P<0.001).

Conclusion

Compared to the healthy group, the ratio of body water to BW was significantly increased in the non-septic infection group, while ECW/BW and ECW/TBW were significantly increased in the sepsis group. These indices could be utilized as diagnostic variables of body water deficit in septic patients.

Ultrasound assessment of muscle mass has potential to identify patients with low muscularity at intensive care unit admission: A retrospective study

BACKGROUND & AIMS

Muscle mass is an important biomarker of survival from a critical illness; however, there is no widely accepted method for routine assessment of low muscularity at intensive care unit (ICU) admission. We hypothesize that ultrasound-based partial muscle mass assessments can reflect the trunk muscle mass. Therefore, we aimed to investigate whether ultrasound muscle mass measurements could reflect trunk muscle mass and identify patients with low muscularity.

METHODS

We performed a retrospective analysis of prospectively obtained ultrasound data at ICU admission. We included patients who underwent computed tomography (CT) imaging at the third lumbar vertebra (L3) within 2 days before and 2 days after ICU admission. Primary outcomes included the correlation between the femoral muscle mass measurements using ultrasound and the cross-sectional area (CSA) at L3 obtained by CT. Low muscularity was defined as a skeletal muscle index of 36.0 cm²/m² for males and 29.0 cm²/m² for females. Secondary outcomes included the correlation with the ultrasound measurements of the biceps brachii muscle mass and diaphragm thickness.

RESULTS

Among 133 patients, 89 underwent CT imaging, which included the L3. The patient mean age was 72 ± 13 years, and 60 patients (67%) were male. The correlation between the femoral muscle ultrasound and CT was ρ = 0.57 (p < 0.01, n = 89) and ρ = 0.48 (p < 0.01, n = 89) for quadriceps muscle layer thickness and rectus femoris muscle CSA, and these had the discriminative power to assess low muscularity, with the areas under the curve of 0.84 and 0.76, respectively. The ultrasound measurements of the biceps brachii muscle mass and diaphragm thickness were correlated with CT imaging [ρ = 0.57-0.60 (p < 0.01, n = 52) and ρ = 0.35 (p < 0.01, n = 79)].

CONCLUSIONS

Ultrasound measurements of muscle mass were correlated with CT measurements, and the measurements of femoral muscle mass were useful to assess low muscularity at ICU admission.

TRIAL REGISTRATION

UMIN000044032 (retrospectively registered on April 25, 2021).

Phase Angle From Bioelectrical Impedance for the Assessment of Sarcopenia in Cirrhosis With or Without Ascites

BACKGROUND AND AIMS

Skeletal muscle index (SMI) from computed tomography (CT) reliably assesses sarcopenia, however, it is expensive and involves serial radiation exposure. Phase angle (PhA) from bioimpedance analysis (BIA) is a noninvasive, low cost, bedside nutritional tool used to monitor changes to nutritional interventions. We aimed to compare the performance of PhA with SMI to assess sarcopenia in cirrhosis.

METHODS

Ambispective cohort study. Consecutive patients with cirrhosis and available images from abdominal CT scan were included. Monofrequency BIA was performed within 2 weeks CT. Spearman's correlation, ROC curve, and survival analysis with Kaplan-Meier, Cox and competing-risk regression were performed.

RESULTS

136 patients were included with a mean age of 54.5 years (60% female). Most had decompensated disease (66%) with ascites in 47%, and a mean MELD of 14 ± 6. We found positive correlations between SMI and PhA (r = 0.58 , P < .001), irrespective of the presence of ascites. The AUROC of PhA-sarcopenia in all patients was 0.702; (0.748 in males,0.677 in females). The best cutoffs of PhA for diagnosing sarcopenia were ≤5.6° in males and ≤5.4° in females. SMI and PhA were significantly associated with survival in Kaplan-Meier curves. In multivariable analyses, SMI was outperformed by age and MELD, whereas PhA remained independently associated with mortality. Considering transplantation as a competing risk, regression analysis showed both SMI and PhA to be independent predictors of mortality (sHR:0.95 [0.90-0.99] and sHR:0.61 [0.42-0.88]).

CONCLUSION

PhA moderately correlates with SMI for the identification of sarcopenia in patients with cirrhosis. However, its prognostic accuracy is comparable to that of SMI, and it is not influenced by ascites.

Bioelectric impedance analysis for body composition measurement and other potential clinical applications in critical illness

PURPOSE OF REVIEW

Insight into body composition is of great value in the ICU. Bioelectric impedance analysis (BIA) is the most applicable bedside technique. However, bioimpedance has not been validated in the critically ill, and the interpretation of the measurements poses challenges. This review discusses the potential clinical applications of BIA and explores caveats and solutions to its use in the intensive care setting.

RECENT FINDINGS

A correlation is repeatedly found between raw impedance parameters, fluid ratios, overhydration, and adverse outcome of critical illness. However, cut-off and reference values remain elusive. Experience with BIA-guided fluid management in the ICU is limited. BIA-derived muscle mass appears a promising biomarker for sarcopenia, correlating well with CT-analysis. Body cell mass and fat-free mass provide potential use in estimation of metabolic rate, protein requirements and pharmacokinetics. Several methods of reducing bias in BIA parameters in critical illness require validation.

SUMMARY

There are currently too many uncertainties and discrepancies regarding interpretation of bioimpedance in critical illness, to justify therapeutic consequences. However, there are several promising areas of research, concerning some of the most urgent clinical problems in intensive care, emphasizing the need to evaluate further the use and interpretation of bioimpedance in the intensive care setting.

Muscle atrophy in critically ill patients : a review of its cause, evaluation, and prevention

Critically ill patients exhibit prominent muscle atrophy, which occurs rapidly after ICU admission and leads to poor clinical outcomes. The extent of atrophy differs among muscles as follows: upper limb: 0.7%-2.4% per day, lower limb: 1.2%-3.0% per day, and diaphragm 1.1%-10.9% per day. This atrophy is caused by numerous risk factors such as inflammation, immobilization, nutrition, hyperglycemia, medication, and mechanical ventilation. Muscle atrophy should be monitored noninvasively by ultrasound at the bedside. Ultrasound can assess muscle mass in most patients, although physical assessment is limited to almost half of all critically ill patients due to impaired consciousness. Important strategies to prevent muscle atrophy are physical therapy and electrical muscular stimulation. Electrical muscular stimulation is especially effective for patients with limited physical therapy. Regarding diaphragm atrophy, mechanical ventilation should be adjusted to maintain spontaneous breathing and titrate inspiratory pressure. However, the sufficient timing and amount of nutritional intervention remain unclear. Further investigation is necessary to prevent muscle atrophy and improve long-term outcomes. J. Med. Invest. 67 : 1-10, February, 2020.

Computed Tomography-Derived Skeletal Muscle Radiodensity Predicts Peak Weight-Corrected Jump Power in Older Adults: The Korean Urban Rural Elderly (KURE) Study

Computed tomography (CT)-derived skeletal muscle area (SMA) and skeletal muscle radiodensity (SMD) reflect distinctive quantitative and qualitative characteristics of skeletal muscles. However, data on whether CT-based muscle parameters, especially SMD, can predict muscle function is limited. In a prospective cohort, 1523 community-dwelling older adults who underwent abdominal CT scans and the countermovement two-legged jumping test on a ground reaction force platform were analyzed (mean age 74.7 years, 65.1% women). SMA and SMD were measured at third lumbar vertebra level (L3). Individuals with low jump power (peak weight-corrected jump power < 23.8 W/kg in men and < 19.0 W/kg in women using clinically validated threshold) were older; had lower SMA, SMD, and maximal grip strength values; and had lower chair rise test and timed up and go test performance than those without low jump power. SMD was positively associated with peak weight-corrected jump power (adjusted β = 0.33 and 0.23 per 1 HU increase in men and women, respectively, p < 0.001). One HU decrement in SMD was associated with 10% elevated odds of low jump power (adjusted OR [aOR] 1.10, p < 0.001) after adjusting for age, sex, height, inflammation, and insulin resistance markers, whereas the association of SMA with low jump power was attenuated (aOR 1.00, p = 0.721). SMD showed better discrimination for low jump power than SMA (AUC 0.699 vs. 0.617, p < 0.001), with additional improvement when added to SMA and conventional risk factors (AUC 0.745 to 0.773, p < 0.001). Therefore, CT-measured L3 SMD can be a sensitive surrogate marker for muscle function along with SMA in older adults, which merits further investigation.

Screening for Sarcopenia (Physical Frailty) in the COVID-19 Era

Although the numbers of aged populations have risen considerably in the last few decades, the current coronavirus disease 2019 (COVID-19) has revealed an extensive vulnerability among these populations. Sarcopenia is an age-related disorder that increases hospitalization, dependencies, and mortality in older adults. It starts to develop in midlife or even earlier as a result of unbalanced diet/poor nutrition and low levels of physical activity, in addition to chronic disorders such as obesity and diabetes mellitus. Given that social isolation is adopted as the most protective measure against COVID-19, the level of physical activity and the intake of adequate diet have considerably declined, especially among older adults-denoting an increased possibility for developing sarcopenia. Research also shows a higher vulnerability of sarcopenic people to COVID-19 as well as the development of wasting disorders such as sarcopenia and cachexia in a considerable proportion of symptomatic and recovering COVID-19 patients. Muscular wasting in COVID-19 is associated with poor prognosis. Accordingly, early detection and proper management of sarcopenia and wasting conditions in older adults and COVID-19 patients may minimize morbidity and mortality during the current COVID-19 crisis. This review explored different aspects of screening for sarcopenia, stressing their relevance to the detection of altered muscular structure and performance in patients with COVID-19. Current guidelines recommend prior evaluation of muscle strength by simple measures such as grip strength to identify individuals with proven weakness who then would be screened for muscle mass loss. The latter is best measured by MRI and CT. However, due to the high cost and radiation risk entailed by these techniques, other simpler and cheaper techniques such as DXA and ultrasound are given preference. Muscle loss in COVID-19 patients was measured during the acute phase by CT scanning of the pectoralis muscle simultaneously during a routine check for lung fibrosis, which seems to be an efficient evaluation of sarcopenia among those patients with no additional cost. In recovering patients, muscle strength and physical performance have been evaluated by electromyography and traditional tests such as the six-minute walk test. Effective preventive and therapeutic interventions are necessary in order to prevent muscle loss and associated physical decline in COVID-19 patients.

Body Composition Analysis as a Predictor of Prognosis for Patients With Acute Kidney Injury Requiring Kidney Replacement Therapy

OBJECTIVES

The aim of this study is to investigate the association between body composition, measured by bioelectrical impedance analysis, and outcomes in patients with acute kidney injury (AKI) receiving kidney replacement therapy (KRT).

METHODS

Patients with severe AKI treated with KRT in our hospital between September 2016 and August 2018 were enrolled. These patients were assessed by body composition analysis before KRT, and on the 3rd day and the 7th day after initiation of KRT. The predictors included lean tissue index (LTI), fat tissue index, and body cell mass index (BCMI). The association between all-cause mortality and predictors was analyzed using Cox regression.

RESULTS

A total of 152 patients were included in this study, with a 28-day mortality of 46.7% and 1-year mortality of 60.5%. LTI (adjusted hazard ratio per standard deviation: 0.37; 95% confidence interval = 0.21-0.66, P < .001) and BCMI (adjusted hazard ratio per standard deviation: 0.37; 95% confidence interval = 0.21-0.67, P < .001) on day 7 after initiation of KRT, rather than before KRT, were associated with mortality during follow-up. LTI and BCMI before KRT were associated with 28-day mortality rather than 1-year mortality.

CONCLUSIONS

LTI and BCMI before KRT were associated with short-term prognosis, and those on day 7 after KRT initiation were associated with intermediate mortality in patients with AKI requiring KRT.

Edema in critically ill patients leads to overestimation of skeletal muscle mass measurements using computed tomography scans

OBJECTIVES

Changes in muscle mass and quality are important targets for nutritional intervention in critical illness. Effects of such interventions may be assessed using sequential computed tomography (CT) scans. However, fluid and lipid infiltration potentially affects muscle area measurements. The aim of this study was to evaluate changes in muscle mass and quality in critical illness with special emphasis on the influence of edema on this assessment.

METHODS

Changes in skeletal muscle area index (SMI) and radiation attenuation (RA) at the level of vertebra L3 were analyzed using sequential CT scans of 77 patients with abdominal sepsis. Additionally, the relation between these changes and disease severity using the maximum Sequential Organ Failure Assessment (SOFA) score and change in edema were studied.

RESULTS

SMI declined on average 0.35%/d (±1.22%; P = 0.013). However, SMI increased in 41.6% of the study population. Increasing edema formation was significantly associated with increased SMI and with a higher SOFA score. Muscle RA decreased during critical illness, but was not significantly associated with changes in SMI or changes in edema.

CONCLUSION

In critically ill patients, edema affects skeletal muscle area measurements, which leads to an overestimation of skeletal muscle area. A higher SOFA score was associated with edema formation. Because both edema and fat infiltration may affect muscle RA, the separate effects of these on muscle quality are difficult to distinguish. When using abdominal CT scans to changes in muscle mass and quality in critically ill patients, researchers must be aware and careful with the interpretation of the results.

Using technology to assess nutritional status and optimize nutrition therapy in critically ill patients

PURPOSE OF REVIEW

Malnutrition is prevalent in critically ill patients and is linked to worse outcomes such as prolonged mechanical ventilation, length of intensive care unit (ICU) stay, and increased mortality. Therefore, nutritional therapy is important. However, it is often difficult to accurately identify those at high malnutrition risk and to optimize nutritional support. Different technological modalities have therefore been developed to identify patients at high nutritional risk and to guide nutritional support in an attempt to optimize outcomes.

RECENT FINDINGS

Computed tomography (CT), ultrasound (US), and bioelectrical impedance analysis are tools that allow assessment of lean body mass and detection of sarcopenia, which is a significant marker of poor nutrition. The use of indirect calorimetry allows the determination of resting energy expenditure to serve as a guide to providing optimal nutrition intake in ICU patients.

SUMMARY

By using CT, US, or bioelectrical impedance analysis, detection of sarcopenia can be undertaken in patients admitted to the ICU. This allows for an accurate picture of underlying nutritional status to help clinicians focus on nutritional support for these patients. Subsequently, indirect calorimetry can be used to guide optimal nutrition therapy and caloric intake in critically ill patients. However, whether these methods result in improved outcomes in critically ill patients remains to be validated.

Status of adult inpatient burn rehabilitation in Europe: Are we neglecting metabolic outcomes?

BACKGROUND

Hypermetabolism, muscle wasting and insulin resistance are challenging yet important rehabilitation targets in the management of burns. In the absence of concrete practice guidelines, however, it remains unclear how these metabolic targets are currently managed. This study aimed to describe the current practice of inpatient rehabilitation across Europe.

METHODS

An electronic survey was distributed by the European Burn Association to burn centres throughout Europe, comprising generic and profession-specific questions directed at therapists, medical doctors and dieticians. Questions concerned exercise prescription, metabolic management and treatment priorities, motivation and knowledge of burn-induced metabolic sequelae. Odds ratios were computed to analyse associations between data derived from the responses of treatment priorities and knowledge of burn-induced metabolic sequelae.

RESULTS

Fifty-nine clinicians with 12.3 ± 9 years of professional experience in burns, representing 18 out of 91 burn centres (response rate, 19.8%) across eight European countries responded. Resistance and aerobic exercises were only provided by 42% and 38% of therapists to intubated patients, 87% and 65% once out-of-bed mobility was possible and 97% and 83% once patients were able to leave their hospital room, respectively. The assessment of resting energy expenditure by indirect calorimetry, muscle wasting and insulin resistance was carried out by only 40.7%, 15.3% and 7.4% respondents, respectively, with large variability in employed frequency and methods. Not all clinicians changed their care in cases of hypermetabolism (59.3%), muscle wasting (70.4%) or insulin resistance (44.4%), and large variations in management strategies were reported. Significant interdisciplinary variation was present in treatment goal importance ratings, motivation and knowledge of burn-induced metabolic sequelae. The prevention of metabolic sequelae was regarded as the least important treatment goal, while the restoration of functional status was rated as the most important. Knowledge of burn-induced metabolic sequelae was linked to higher importance ratings of metabolic sequelae as a therapy goal (odds ratio, 4.63; 95% CI, 1.50-14.25; p < 0.01).

CONCLUSION

This survey reveals considerable non-uniformity around multiple aspects of inpatient rehabilitation across European burn care, including, most notably, a potential neglect of metabolic outcomes. The results contribute to the necessary groundwork to formulate practice guidelines for inpatient burn rehabilitation.

Association of bioelectric impedance analysis body composition and disease severity in COVID-19 hospital ward and ICU patients: The BIAC-19 study

Background

The current severe acute respiratory syndrome coronavirus 2 pandemic is unprecedented in its impact. It is essential to shed light on patient characteristics that predispose to a more severe disease course. Obesity, defined as a BMI>30 kg/m², is suggested to be one of these characteristics. However, BMI does not differentiate between fat mass and lean body mass, or the distribution of fat tissue. The aim of the present study was to assess the body composition of COVID-19 patients admitted to the ward or the ICU and identify any associations with severity of disease.

Methods

We performed an observational cross-sectional cohort study. Bioelectric impedance analysis was conducted amongst all confirmed COVID-19 patients admitted to the ward or ICU of our hospital in the Netherlands, between April 10 and 17, 2020. Body water measurements and derived values were recalculated to dry weight, using a standard ratio of extracellular water to total body water of 0.38. Data were compared between the ward and ICU patients, and regression models were used to assess the associations between baseline characteristics, body composition, and several indicators of disease severity, including a composite score composed of mortality, morbidity, and ICU admission.

Results

Fifty-four patients were included, of which 30 in the ward and 24 in the ICU. The mean age was 67 years (95%-CI 64–71), and 34 (63%) were male. Mean BMI was 29.7 (95%-CI 28.2–31.1) kg/m² and did not differ between groups. Body composition values were not independently associated with disease severity. In multiple logistic regression analyses, a low phase angle was associated with COVID-19 severity in the composite score (OR 0.299, p = 0.046).

Conclusion

We found no significant associations between body composition, including fat mass, visceral fat area, and fat-free mass, and disease severity in our population of generally overweight COVID-19 patients. A lower phase angle did increase the odds of severe COVID-19. We believe that factors other than body composition play a more critical role in the development of severe COVID-19.

Antioxidants in Sport Sarcopenia

The decline of skeletal muscle mass and strength that leads to sarcopenia is a pathology that might represent an emergency healthcare issue in future years. Decreased muscle mass is also a condition that mainly affects master athletes involved in endurance physical activities. Skeletal muscles respond to exercise by reshaping the biochemical, morphological, and physiological state of myofibrils. Adaptive responses involve the activation of intracellular signaling pathways and genetic reprogramming, causing alterations in contractile properties, metabolic status, and muscle mass. One of the mechanisms leading to sarcopenia is an increase in reactive oxygen and nitrogen species levels and a reduction in enzymatic antioxidant protection. The present review shows the recent experimental models of sarcopenia that explore molecular mechanisms. Furthermore, the clinical aspect of sport sarcopenia will be highlighted, and new strategies based on nutritional supplements, which may contribute to reducing indices of oxidative stress by reinforcing natural endogenous protection, will be suggested.

How does muscularity assessed by bedside methods compare to computed tomography muscle area at intensive care unit admission? A pilot prospective cross-sectional study

BACKGROUND

Low muscularity and malnutrition at intensive care unit (ICU) admission have been associated with negative clinical outcomes. There are limited data available evaluating the validity of bedside techniques to measure muscle mass in critically ill adults. We aimed to compare bedside methods for muscle mass assessment [bioimpedance spectroscopy (BIS), arm anthropometry and subjective physical assessment] against reference technology [computed tomography (CT)] at ICU admission.

METHODS

Adults who had CT scanning at the third lumbar area <72 h after ICU admission were prospectively recruited. Bedside methods were performed within 48 h of the CT scan. Pearson's correlation compared CT muscle area with BIS-derived fat-free mass (FFM) (kg) and FFM-Chamney (kg) (adjusted for overhydration), mid-upper arm circumference (cm) and mid-arm muscle circumference (cm). Depleted muscle stores were determined using published thresholds for each method. Cohen's kappa (κ) was used to evaluate the agreement between bedside and CT assessment of muscularity status (normal or low).

RESULTS

Fifty participants were enrolled. There were strong correlations between CT muscle area and FFM values and mid-arm muscle circumference (P < 0.001). Using FFM-Chamney, all six (100%) participants with low CT muscle area were detected (κ = 0.723). FFM-BIS, arm anthropometry and subjective physical assessment methods detected 28%-38% of participants with low CT muscle area.

CONCLUSIONS

BIS-derived FFM using an adjustment algorithm for overhydration was correlated with CT muscle area and had good agreement with muscularity status assessed by CT image analysis. Arm anthropometry and subjective physical assessment techniques were not able to reliably detect participants with low CT muscle area.

Quantifying Response to Nutrition Therapy During Critical Illness: Implications for Clinical Practice and Research? A Narrative Review

Critical illness causes substantial muscle loss that adversely impacts recovery and health-related quality of life. Treatments are therefore needed that reduce mortality and/or improve the quality of survivorship. The purpose of this Review is to describe both patient-centered and surrogate outcomes that quantify responses to nutrition therapy in critically ill patients. The use of these outcomes in randomized clinical trials will be described and the strengths and limitations of these outcomes detailed. Outcomes used to quantify the response of nutrition therapy must have a plausible mechanistic relationship to nutrition therapy and either be an accepted measure for the quality of survivorship or highly likely to lead to improvements in survivorship. This Review identified that previous trials have utilized diverse outcomes. The variety of outcomes observed is probably due to a lack of consensus as to the most appropriate surrogate outcomes to quantify response to nutrition therapy during research or clinical practice. Recent studies have used, with some success, measures of muscle mass to evaluate and monitor nutrition interventions administered to critically ill patients.

Monitoring of muscle mass in critically ill patients: comparison of ultrasound and two bioelectrical impedance analysis devices

Background

Skeletal muscle atrophy commonly occurs in critically ill patients, and decreased muscle mass is associated with worse clinical outcomes. Muscle mass can be assessed using various tools, including ultrasound and bioelectrical impedance analysis (BIA). However, the effectiveness of muscle mass monitoring is unclear in critically ill patients. This study was conducted to compare ultrasound and BIA for the monitoring of muscle mass in critically ill patients.

Methods

We recruited adult patients who were expected to undergo mechanical ventilation for > 48 h and to remain in the intensive care unit (ICU) for > 5 days. On days 1, 3, 5, 7, and 10, muscle mass was evaluated using an ultrasound and two BIA devices (Bioscan: Malton International, England; Physion: Nippon Shooter, Japan). The influence of fluid balance was also evaluated between each measurement day.

Results

We analyzed 93 images in 21 patients. The age of the patients was 69 (interquartile range, IQR, 59–74) years, with 16 men and 5 women. The length of ICU stay was 11 days (IQR, 9–25 days). The muscle mass, monitored by ultrasound, decreased progressively by 9.2% (95% confidence interval (CI), 5.9–12.5%), 12.7% (95% CI, 9.3–16.1%), 18.2% (95% CI, 14.7–21.6%), and 21.8% (95% CI, 17.9–25.7%) on days 3, 5, 7, and 10 (p <  0.01), respectively, with no influence of fluid balance (r = 0.04, p = 0.74). The muscle mass did not decrease significantly in both the BIA devices (Bioscan, p = 0.14; Physion, p = 0.60), and an influence of fluid balance was observed (Bioscan, r = 0.37, p <  0.01; Physion, r = 0.51, p <  0.01). The muscle mass assessment at one point between ultrasound and BIA was moderately correlated (Bioscan, r = 0.51, p <  0.01; Physion, r = 0.37, p <  0.01), but the change of muscle mass in the same patient did not correlate between these two devices (Bioscan, r = − 0.05, p = 0.69; Physion, r = 0.23, p = 0.07).

Conclusions

Ultrasound is suitable for sequential monitoring of muscle atrophy in critically ill patients. Monitoring by BIA should be carefully interpreted owing to the influence of fluid change.

Trial registration

UMIN000031316. Retrospectively registered on 15 February 2018.

Evaluation of the association between decreased skeletal muscle mass and extubation failure after long-term mechanical ventilation

BACKGROUND & AIMS

Elderly patients are being increasingly admitted to the intensive care unit (ICU) for mechanical ventilation (MV) and prevalence of decreased skeletal muscle mass which develop with aging is subsequently increasing. The objective of this study was to identify the association between decreased skeletal muscle mass and extubation failure in patients undergoing long-term MV.

METHODS

Adults (≥18 years of age) with long-term MV for > 7 days between January 2014 and February 2019 were included retrospectively. Patients who died or were transferred with MV, underwent tracheostomy with failure of weaning from MV, and had not undergone abdominal computed tomography within 3 days before or after intubation were excluded. Failed extubation was defined as reintubation within 48 h after extubation following long-term MV for >7 days. We divided the patients into extubation success and failure groups.

RESULTS

Parameters including patients' demographics, cause of intubation, initial setting of MV, maximum inspiratory pressure (MIP) and rapid shallow breath index (RSBI) at extubation, and skeletal muscle mass were compared between the two groups. Decreased skeletal muscle mass was set a standard as a L3 muscle index of less than 49 cm²/m² for men and of less than 31 cm²/m² for women using Korean-specific cut-offs for sarcopenia as evaluated on previous epidemiologic study. Among 104 patients who were screened, 45 were included, and 11 (24.4%) failed to be extubated. Mean MIP (23.5 ± 11.8 vs. 32.4 ± 9.3, p = 0.134) and RSBI (57.2 ± 26.5 vs. 55.3 ± 20.4, p = 0.803) were not different between the two groups. The proportions of patients whose MIP or RSBI satisfied the cutoff for extubation were not different between the groups. There were no significant differences in age, sex, body mass index, comorbidities, nutritional status, and cause of intubation between the two groups. The extubation failure group showed a higher proportion of decreased skeletal muscle mass (90.9% vs. 58.8%, p = 0.05) and longer duration of MV (10.7 ± 4.1 vs. 9.6 ± 3.4, p < 0.001) than the extubation success group. Multivariate analysis showed that the duration of intubation (OR = 1.439, 95% CI = 1.12-1.85), and decreased skeletal muscle mass (OR = 24.382, 95% CI = 1.00-594.86) were associated with extubation failure.

CONCLUSIONS

Decreased skeletal muscle mass was associated with extubation failure after long-term MV for > 7 days. It is important to diagnose decreased skeletal muscle mass in critically ill patients to reduce extubation failure rates.

Identifying critically ill patients with low muscle mass: Agreement between bioelectrical impedance analysis and computed tomography

BACKGROUND & AIMS

Low muscle mass and -quality on ICU admission, as assessed by muscle area and -density on CT-scanning at lumbar level 3 (L3), are associated with increased mortality. However, CT-scan analysis is not feasible for standard care. Bioelectrical impedance analysis (BIA) assesses body composition by incorporating the raw measurements resistance, reactance, and phase angle in equations. Our purpose was to compare BIA- and CT-derived muscle mass, to determine whether BIA identified the patients with low skeletal muscle area on CT-scan, and to determine the relation between raw BIA and raw CT measurements.

METHODS

This prospective observational study included adult intensive care patients with an abdominal CT-scan. CT-scans were analysed at L3 level for skeletal muscle area (cm²) and skeletal muscle density (Hounsfield Units). Muscle area was converted to muscle mass (kg) using the Shen equation (MM_CT). BIA was performed within 72 h of the CT-scan. BIA-derived muscle mass was calculated by three equations: Talluri (MM_Talluri), Janssen (MM_Janssen), and Kyle (MM_Kyle). To compare BIA- and CT-derived muscle mass correlations, bias, and limits of agreement were calculated. To test whether BIA identifies low skeletal muscle area on CT-scan, ROC-curves were constructed. Furthermore, raw BIA and CT measurements, were correlated and raw CT-measurements were compared between groups with normal and low phase angle.

RESULTS

110 patients were included. Mean age 59 ± 17 years, mean APACHE II score 17 (11-25); 68% male. MM_Talluri and MM_Janssen were significantly higher (36.0 ± 9.9 kg and 31.5 ± 7.8 kg, respectively) and MM_Kyle significantly lower (25.2 ± 5.6 kg) than MM_CT (29.2 ± 6.7 kg). For all BIA-derived muscle mass equations, a proportional bias was apparent with increasing disagreement at higher muscle mass. MM_Talluri correlated strongest with CT-derived muscle mass (r = 0.834, p < 0.001) and had good discriminative capacity to identify patients with low skeletal muscle area on CT-scan (AUC: 0.919 for males; 0.912 for females). Of the raw measurements, phase angle and skeletal muscle density correlated best (r = 0.701, p < 0.001). CT-derived skeletal muscle area and -density were significantly lower in patients with low compared to normal phase angle.

CONCLUSIONS

Although correlated, absolute values of BIA- and CT-derived muscle mass disagree, especially in the high muscle mass range. However, BIA and CT identified the same critically ill population with low skeletal muscle area on CT-scan. Furthermore, low phase angle corresponded to low skeletal muscle area and -density.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02555670).